What is reality, really?

Abstract

This is not a question about the meaning of life. That is whatever you decide to make it, and is a topic for discussion in the bar, not a book about science. Nor is this a purely metaphysical question, although it covers areas that have traditionally been the domain of philosophers. Instead, this is a question about the true nature of the Universe. At its heart is the ultimate, and for now totally unanswerable, question, why should there be anything here at all? As the physicist Stephen Hawking wrote, ‘What is it that breathes fire into the equations? Why does the Universe go to all the bother of existing?’.